The present disclosure relates to devices and methods for detecting neutrons and/or gamma radiation.
The worldwide expansion of nuclear energy to produce carbon-free electricity comes with the risk of nuclear proliferation. The advancement in deterring technologies, especially the ability to detect special nuclear materials, is critical in mitigating risks.
Nuclear radiation detection and/or monitoring is also critical in many other industries including hospitals where neutron and/or proton therapies are used, the nuclear energy industry, the scientific research industry, etc. Since neutrons are electrically neutral, detection generally requires a conversion medium which emits electrically charged particles upon exposure to neutrons.
Compressed helium-3 (3He) is widely used as a standard medium for detecting neutrons, largely because of its large thermal neutron cross-section and insensitivity to gamma radiation, high efficiency, and durability. However, the high demand for 3He in homeland security and nonproliferation applications, and its widespread use in technologies such as cryogenics, spallation neutron sources, and magnetic resonance imaging (MRI) have caused a long-standing shortage of 3He. Thus, a replacement is urgently needed.
Alternatives such as boron-10 (10B) and lithium-6 (6Li) can be applied as coatings or dopants in compounds. However, they suffer from inefficiency caused by comparatively long neutron mean free paths relative to the short ranges of charged particles in the neutron conversion media and relatively low neutron capture cross-sections compared with Gd.
The conversion medium may be disposed in a semiconductor device. A measurement of current or voltage may be used in detecting neutron radiation. However, some semiconductor materials are sensitive to gamma radiation which makes isolating neutron radiation difficult. Additionally, 3He is a relatively scarce material.
It would be desirable to develop new devices and methods for neutron detection with gamma discrimination and/or gamma radiation detection.